Chemical detection unit



FIG. 1 shows a front view of a chemical detection unit;

FIG. 2 shows a rear view thereof;

FIG. 3 shows a second front view thereof;

FIG. 4 shows a second rear view thereof;

FIG. 5 shows a right side view thereof;

FIG. 6 shows a left side view thereof;

FIG. 7 shows a top view thereof; and,

FIG. 8 shows a bottom view thereof.

The dashed lines are for the purpose of illustrating portions of the chemical detection unit and form no part of the claimed design. The dotted lines on the surface portions indicate contour and not surface decoration. 

CLAIM The ornamental design for a chemical detection unit, as shown and described. 